Understanding and Enforcing Opacity
Paper in proceeding, 2015

This paper puts a spotlight on the specification and enforcement of opacity, a security policy for protecting sensitive properties of system behavior. We illustrate the fine granularity of the opacity policy by location privacy and privacy-preserving aggregation scenarios. We present a framework for opacity and explore its key differences and formal connections with such well-known information-flow models as noninterference, knowledge-based security, and declassification. Our results are machine-checked and parameterized in the observational power of the attacker, including progress-insensitive, progress-sensitive, and timing-sensitive attackers. We present two approaches to enforcing opacity: a whitebox monitor and a blackbox sampling-based enforcement. We report on experiments with prototypes that utilize state-of-the-art Satisfiability Modulo Theories (SMT) solvers and the random testing tool QuickCheck to establish opacity for the location and aggregation-based scenarios.


Daniel Schoepe

Chalmers, Computer Science and Engineering (Chalmers), Computing Science (Chalmers)

Andrei Sabelfeld

Chalmers, Computer Science and Engineering (Chalmers), Software Technology (Chalmers)

28th IEEE Computer Security Foundations Symposium, CSF 2015, Verona, Italy, 13 July-17 July

1063-6900 (ISSN)

Vol. 2015-September 539-553
978-146737538-2 (ISBN)

Areas of Advance

Information and Communication Technology

Subject Categories

Computer and Information Science


Basic sciences





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